Geomechanics for Energy and the Environment最新文献

Study on novel alkali-activated cementitious grout for scour control of offshore foundation

IF 3.3 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-03-11 DOI: 10.1016/j.gete.2025.100663

Fei Sha , Yulong Dong , Shijiu Gu , Xiaochen Fan , Wenwen Xiao

To address scour hazards surrounding offshore foundations, a new method employing novel alkali-activated cementitious grout (AACG) has been proposed for improvement of seabed soil. Ground granulated blast-furnace slag (GGBFS) was replaced by fly ash (FA), steel slag (SS) or FA + SS to prepare precursors, the replacement amounts were 10 %, 20 %, 30 % and 40 %. Fresh-state and mechanical properties, minerals and microstructures were investigated. A novel scour simulation test device was developed to simulate engineering conditions of scour and remediation. Flow-soil coupled scour resistance tests were conducted, shear tests and SEM measurements of solidified soil were carried out. The results showed that the optimal ratio of GGBFS:FA:SS was 6:2:2 for AACG. The optimized AACG has better fluidity and lower brittleness, and its 28 d unconfined compressive strength (UCS) achieves 13.5 MPa. For AACG solidified soil, the maximum scour depth was reduced by 33.3 % and the maximum sediment transport amount was decreased by 53.2 %, which were compared to those of cement - sodium silicate (C-S) double slurry. Moreover, the increase degrees of internal friction angle, cohesion and critical shear stress were 700 %, 7.9 % and 786 %, respectively. The scour resistance of AACG solidified soil was superior. The inherent relationship between UCS and critical shear stress was discussed. UCS can be used to rapidly assess the scour resistance of consolidated soil. This study introduced an eco-friendly AACG as an innovative stabilizer for soil reinforcement around offshore structural foundations, offering significant application and environmental values for scour control.

为解决近海地基周围的冲刷危险，有人提出了一种采用新型碱活性水泥基灌浆料（AACG）的新方法来改良海底土壤。用粉煤灰（FA）、钢渣（SS）或 FA + SS 取代磨细高炉矿渣（GGBFS）来制备前驱体，取代量分别为 10%、20%、30% 和 40%。对新鲜状态和机械性能、矿物和微观结构进行了研究。开发了一种新型冲刷模拟试验装置，用于模拟冲刷和修复的工程条件。进行了流动-土壤耦合抗冲刷试验，并对固化土壤进行了剪切试验和扫描电镜测量。结果表明，对于 AACG 而言，GGBFS:FA:SS 的最佳比例为 6:2:2。优化后的 AACG 具有更好的流动性和更低的脆性，其 28 d 的无侧限抗压强度（UCS）达到 13.5 MPa。与水泥-硅酸钠（C-S）双水泥浆相比，AACG 固化土的最大冲刷深度减少了 33.3%，最大泥沙输移量减少了 53.2%。此外，内摩擦角、内聚力和临界剪应力分别增加了 700%、7.9% 和 786%。AACG 固化土的抗冲刷性更优越。讨论了 UCS 与临界剪应力之间的内在关系。UCS 可用于快速评估固结土的抗冲刷性。这项研究介绍了一种生态友好型 AACG，作为一种创新的稳定剂用于近海结构地基周围的土壤加固，在冲刷控制方面具有重要的应用价值和环境价值。

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引用次数: 0

Designing a repository in domal salt: The influence of design variants in different modelling environments

IF 3.3 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-03-11 DOI: 10.1016/j.gete.2025.100659

Jeroen Bartol , Dirk-Alexander Becker , Steven Benbow , Alexander Bond , Tanja Frank , Tara LaForce , Josh Nicholas , Richard Jayne , Philip H. Stauffer , Emily Stein , Jodie Stone , Jens Wolf

To understand the long-term environmental impact of disposing radioactive waste of in a deep geological repository and to optimise its design, performance assessments are used. In this study, four teams (COVRA, GRS, Quintessa, and DOE) modified the previously developed generic repository of DECOVALEX task F2 to identify commonalities and differences between the teams for specific changes in repository design. The teams tested six design modifications: (1) Replacing concrete abutments with run-of-mine salt; (2) Replacing the salt seal with a concrete abutment and using run-of-mine salt instead for the two concrete abutments in each drift seal; (3) Halving the size of the infrastructure area; (4) Using run-of-mine salt instead of gravel for backfilling the infrastructure area; (5) Disposal of spent nuclear fuel without the POLLUX-10 containers (6); Lower initial saturation of the spent nuclear fuel and vitrified waste disposal drifts. Despite different modelling strategies used, models agreed that a smaller infrastructure area has a limited effect on radionuclide transport. Responses to the absence of the two concrete abutments in each seal, the use of single large concrete abutments (200 m each), or the use of run-of-mine salt in the infrastructure area differ between teams due to differing modelling assumptions. Based on these results, the estimated efficacy of containment depends strongly on the model assumptions of each team. More specifically, it appears to depend on the compaction model used and therefore on the backfill material used in different areas of the repository. However, the drift seal appears to be a critical design element in all models, effectively limiting radionuclide transport by hydrologically disconnecting sections of the repository. Additional beneficial design choices include the use of dry salt in disposal drifts to limit radionuclide transport and reducing the infrastructure area costs and minimizing host rock damage.

{"title":"Designing a repository in domal salt: The influence of design variants in different modelling environments","authors":"Jeroen Bartol , Dirk-Alexander Becker , Steven Benbow , Alexander Bond , Tanja Frank , Tara LaForce , Josh Nicholas , Richard Jayne , Philip H. Stauffer , Emily Stein , Jodie Stone , Jens Wolf","doi":"10.1016/j.gete.2025.100659","DOIUrl":"10.1016/j.gete.2025.100659","url":null,"abstract":"<div><div>To understand the long-term environmental impact of disposing radioactive waste of in a deep geological repository and to optimise its design, performance assessments are used. In this study, four teams (COVRA, GRS, Quintessa, and DOE) modified the previously developed generic repository of DECOVALEX task F2 to identify commonalities and differences between the teams for specific changes in repository design. The teams tested six design modifications: (1) Replacing concrete abutments with run-of-mine salt; (2) Replacing the salt seal with a concrete abutment and using run-of-mine salt instead for the two concrete abutments in each drift seal; (3) Halving the size of the infrastructure area; (4) Using run-of-mine salt instead of gravel for backfilling the infrastructure area; (5) Disposal of spent nuclear fuel without the POLLUX-10 containers (6); Lower initial saturation of the spent nuclear fuel and vitrified waste disposal drifts. Despite different modelling strategies used, models agreed that a smaller infrastructure area has a limited effect on radionuclide transport. Responses to the absence of the two concrete abutments in each seal, the use of single large concrete abutments (200 m each), or the use of run-of-mine salt in the infrastructure area differ between teams due to differing modelling assumptions. Based on these results, the estimated efficacy of containment depends strongly on the model assumptions of each team. More specifically, it appears to depend on the compaction model used and therefore on the backfill material used in different areas of the repository. However, the drift seal appears to be a critical design element in all models, effectively limiting radionuclide transport by hydrologically disconnecting sections of the repository. Additional beneficial design choices include the use of dry salt in disposal drifts to limit radionuclide transport and reducing the infrastructure area costs and minimizing host rock damage.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"42 ","pages":"Article 100659"},"PeriodicalIF":3.3,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental study of evaporation from soil-atmosphere interfaces

IF 3.3 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-03-10 DOI: 10.1016/j.gete.2025.100658

Jaime E. Granados , Catalina Lozada , Bernardo Caicedo

Experimental evaporation tests on 2–20 mm soil samples were performed under a wide range of atmospheric conditions using a climatic chamber. The relatively thin thickness of the samples was intended to represent the soil-atmosphere interface layer. Atmospheric conditions of wind velocity, air temperature, relative humidity and irradiance were imposed on bare soil surfaces of sand, compacted clay and kaolin slurry. The results of an extensive number of experimental tests show a good correlation between the atmospheric conditions measured near the soil surface and Potential Evaporation (PE) and soil initial evaporation rates. An empirical model based on an inverse sigmoid function is proposed to express the ratio between Actual Evaporation (AE) and Potential Evaporation (AE/PE) rates versus soil suction. The evaporation results of the present study may be used to predict PE and AE rates from soil surfaces of different textures under a broad range of environmental conditions. The empirical model may be used in soil-atmosphere interaction models to estimate water flux across soil-atmosphere boundaries.

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引用次数: 0

Settlement analysis in the context of underground climate change

IF 3.3 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-03-10 DOI: 10.1016/j.gete.2025.100662

Anjali N. Thota, Alessandro F. Rotta Loria

Subsurface urban heat islands are a pressing global issue responsible for an underground climate change beneath cities. Over the past two decades, this phenomenon has been identified as a threat to subsurface ecosystems, hydrogeological systems, transportation systems, and public health. Recently, underground climate change has also been reported as a silent hazard for civil infrastructure due to thermally induced ground deformations. This paper expands the study of the impacts of underground climate change on civil infrastructure by presenting a simplified, one-dimensional settlement analysis that simulates the deformations driven by subsurface urban heat islands as a viscous process driven by thermally accelerated creep. Specifically, this investigation focuses on the vertical displacements of the ground surrounding a caisson foundation supporting a 39-storey building located in the Chicago Loop district under the influence of underground climate change for 100 years. The results reveal that the thermally induced ground displacements caused by underground climate change can be substantial and strongly depend on the ground warming rate and the spatial extent of subterranean temperature variations. The study provides new evidence about the relevance of underground climate change for the serviceability performance of civil infrastructure, motivating future research to identify which types of earth-contact structures and infrastructures may be particularly affected by thermally induced ground deformations caused by this phenomenon.

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引用次数: 0

The influence of hydrating mineral components on wellbore sealing capacity of salt-plugged wells

IF 3.3 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-03-08 DOI: 10.1016/j.gete.2025.100661

Suzanne J.T. Hangx, Timotheus K.T. Wolterbeek , Max J. Bruggeman , Oliver Plümper

Rock salt forms an important hydrocarbon caprock and a source for salt (solution) mining. With many associated wells approaching the end of their lifetime, effective Plugging & Abandonment strategies are required. At the same time, as the energy transition progresses, many new wells will likely be drilled for specific use during geological CO₂ storage or temporary hydrogen storage. These wells, too, will eventually need to be plugged and abandoned safely. We investigated the sealing effectiveness of a potential alternative for Portland cement as plugging material, consisting of a mixture of metal oxides (CaO, MgO) and salt (NaCl), wherein hydration leads to significant volumetric expansions. In 11 out of 17 flow-through experiments, the apparent plug permeability fell to 10⁻¹⁷–10⁻¹⁸ m² upon hydration, under differential pressures of 0.2–1.8 MPa. One CaO:NaCl sample could withstand up to 2 MPa differential pressure across its 5-cm-length, attaining a minimum apparent permeability of 10⁻²¹ m². Apparent plug permeability correlated closely with the expected final solid volume fraction, i.e., the amount of void space remaining. Upscaling to realistic wellbore dimensions (10–100 m) suggests that expanding metal oxide-salt plugs set in steel casing could withstand differential pressures of 3.6–40 MPa/m. For evaporitic caprocks, this implies that metal oxide-salt plugs can be a potential alternative to conventional Portland cement, ensuring plug closure and potentially sealing within several hours. However, sealing highly depends on the amount of metal oxide available and the volume of void space requiring closure.

{"title":"The influence of hydrating mineral components on wellbore sealing capacity of salt-plugged wells","authors":"Suzanne J.T. Hangx, Timotheus K.T. Wolterbeek , Max J. Bruggeman , Oliver Plümper","doi":"10.1016/j.gete.2025.100661","DOIUrl":"10.1016/j.gete.2025.100661","url":null,"abstract":"<div><div>Rock salt forms an important hydrocarbon caprock and a source for salt (solution) mining. With many associated wells approaching the end of their lifetime, effective <em>Plugging & Abandonment</em> strategies are required. At the same time, as the energy transition progresses, many new wells will likely be drilled for specific use during geological CO<sub>2</sub> storage or temporary hydrogen storage. These wells, too, will eventually need to be plugged and abandoned safely. We investigated the sealing effectiveness of a potential alternative for Portland cement as plugging material, consisting of a mixture of metal oxides (CaO, MgO) and salt (NaCl), wherein hydration leads to significant volumetric expansions. In 11 out of 17 flow-through experiments, the apparent plug permeability fell to 10<sup>−17</sup>–10<sup>−18</sup> m<sup>2</sup> upon hydration, under differential pressures of 0.2–1.8 MPa. One CaO:NaCl sample could withstand up to 2 MPa differential pressure across its 5-cm-length, attaining a minimum apparent permeability of 10<sup>−21</sup> m<sup>2</sup>. Apparent plug permeability correlated closely with the expected final solid volume fraction, i.e., the amount of void space remaining. Upscaling to realistic wellbore dimensions (10–100 m) suggests that expanding metal oxide-salt plugs set in steel casing could withstand differential pressures of 3.6–40 MPa/m. For evaporitic caprocks, this implies that metal oxide-salt plugs can be a potential alternative to conventional Portland cement, ensuring plug closure and potentially sealing within several hours. However, sealing highly depends on the amount of metal oxide available and the volume of void space requiring closure.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"42 ","pages":"Article 100661"},"PeriodicalIF":3.3,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Quantitative assessment of rock plane replica orientation detection and extraction methods under controlled experimental conditions

IF 3.3 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-03-08 DOI: 10.1016/j.gete.2025.100649

Nirandoal Cheng , Tan Yon Ken , Mohd Ashraf Mohamad Ismail , Fatin Nadhirah Ahmad Pauzi , Nursyahirah Mohd Saleh , Yasuhiro Yokota

The characterization of discontinuous rock mass properties is essential for understanding the behaviour of rock masses in various engineering applications, such as tunnelling, mining, and slope stability analysis. This study presents an innovative approach for detecting and extracting the orientations of discontinuous rock plane replicas using image analysis techniques. The image analysis technique employed in this research involves the use of advanced algorithms in Agisoft Metashape to process digital dense point clouds, enabling the identification of discontinuities and the extraction of dip and dip direction in CloudCompare software. The performance of the image analysis technique was evaluated using the Root Mean Square Error (RMSE) for dip and dip direction measurements. The RMSE values were 1.97 for dip and 2.34 for dip direction, indicating high accuracy and reliability in-plane detection. Additionally, the range of differences observed was within 5 degrees for dip and within 13 degrees for dip direction. These results support the interpretation of RMSE, highlighting the sensitivity of dip direction in image analysis.

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引用次数: 0

Impact of flow direction and soil characteristics on suffusion susceptibility: Analyzing soil resistance and filtration effects

IF 3.3 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-03-08 DOI: 10.1016/j.gete.2025.100657

Dinh Minh Tran , Didier Marot , Fateh Bendahmane , Rachel Gelet

Most suffusion tests described in the literature are performed by applying a vertical flow to homogenous specimens, whereas on site, the flow can be in another direction and the soil may display local variations of density and grain size distribution. A series of suffusion tests are performed with a multi-direction flow device, under vertical or horizontal flow. Two cohesionless soils which slightly differ by their grain size distribution and density are tested. Specimens are either composed of a single soil or bi-layered, i.e. a layer of each soil. The suffusion susceptibility is characterized by two critical hydraulic gradients and an erosion resistance index. With the current testing procedure, the influence of the local density variations on the suffusion susceptibility is not significant. The results show that under horizontal flow, each tested soil becomes more heterogeneous, but also slightly more resistant towards suffusion. When considering bi-layered specimens and a flow parallel to the soil interface, the suffusion susceptibility is mainly controlled by the most erodible soil. On the other hand, when the flow is perpendicular to the soil interface, the suffusion susceptibility is mainly controlled by the most resistant soil. The results also highlight the influence of pore opening on the filtration and the selection of the pore opening of the downstream filter is discussed.

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引用次数: 0

Analysis of short- and long-term coupled THM behaviours in argillaceous rock for nuclear waste disposal

IF 3.3 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-03-07 DOI: 10.1016/j.gete.2025.100660

Fei Song , Antonio Gens , Stefano Collico , Carlos Plúa , Gilles Armand , Huaning Wang

Deep geological disposal is recognised as the most feasible method for the management of High-level Nuclear Waste (HLW). This study involved the performance of numerical analyses to evaluate the short- and long-term Thermo-Hydro-Mechanical (THM) behaviour of HLW disposals at the repository scale. A far-field numerical model is analysed, considering geological profiles 1000 m deep from the surface. In the analyses, an elasto-viscoplastic constitutive model is employed to characterize the behaviour of the argillaceous host rock, taking into account hardening-softening behaviour, anisotropy of THM properties, as well as permeability variation due to damage. Generalized Darcy’s law and Fourier’s law are utilized to represent the liquid and heat fluxes, respectively. Wide-ranging parametric analyses are performed to investigate the effect of spacing between parallel microtunnels and of different multi-physics interactions on the evolution of THM behaviour at the repository scale. Variations in spacing significantly impact the temperature and pore pressure fields, which in turn influence the development of potential damage zones. An enhanced understanding of the THM mechanisms associated with the short-term and long-term stability of nuclear waste disposals has been achieved in this study, therefore, providing valuable insights for the design and optimization of the geological repositories.

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引用次数: 0

Safety assessment for a geological disposal facility in domal salt: The Dutch case 多金属盐地质弃置设施的安全评估：荷兰案例

IF 3.3 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-03-01 DOI: 10.1016/j.gete.2025.100645

Jeroen Bartol, Marja Vuorio

In the Netherlands, all radioactive waste is currently collected and stored above ground for at least 100 years by COVRA. After 100 years, all radioactive waste must be permanently disposed of. One option for permanent disposal currently considered is a purpose-built geological disposal facility in rock salt, where a combination of natural and engineered barriers is expected to provide the necessary safety. Rock salt, as a natural barrier, is considered impermeable when undisturbed. Therefore, radionuclides can only reach the surface via the mined openings of the geological disposal facility. Here, multiple engineered barriers provide the necessary safety. In the short term, these include concrete seals, HLW packages, and waste forms. In the long term, moisturized granular salt backfill provides containment. Here, we present the safety assessment of a geological disposal facility in rock salt, using the updated Dutch disposal concept and waste inventory. In total, seven different scenarios are modelled: the (1) normal evolution scenario in which the geological disposal facility evolves as expected, and six alternative scenarios: failure of (2) the high level waste packages, (3) failure of the tunnel seals, (4) failure of the spiral ramp seal, (5) flow path between a brine pocket and mine excavations, (6) less probable characteristics of radionuclide mobilization and transport, (7) and reduced long-term sealing by backfill. Model results show that when the geological disposal facility evolves as expected, no release of radionuclides is expected. Likewise, no release is expected in the six alternative scenarios, although differences exist in the extent to which radionuclides are able to travel within the geological disposal facility. These results indicate that the engineered barriers, combined with the natural barrier of the rock salt, are effective in isolating and providing containment during at the least the first million years after closure.

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引用次数: 0

Numerical simulation of copper-contaminated sediment consolidation and remediation through vacuum electro-osmosis 铜污染沉积物固结和真空电渗修复的数值模拟

IF 3.3 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-03-01 DOI: 10.1016/j.gete.2025.100655

Yang Shen, Wencheng Qi, Shaoyu Li, Zilin Yang, Kaijia Chen

The combination of vacuum electro-osmosis treatment and electrokinetic remediation allows for the simultaneous consolidation and remediation of contaminated sediments, involving multiple coupled fields such as electrical field, hydraulic field, mechanical field, and chemical field. This study couples the charge conservation, vacuum electro-osmosis consolidation, and contaminant transport equations under vacuum electro-osmosis conditions to establish a numerical model for the consolidation and remediation process. Laboratory experiments were conducted for comparative analyses. The numerical results show that the electric field intensity decays from both sides towards the center. However, the other positions align well with the experimental results, indicating the ability of the numerical model to reflect the non-uniform distribution of soil potential. The anode and cathode regions become negative pressure centers, resulting in an increasing seepage velocity towards the negative pressure centers. The numerical results accurately capture the trend of pore water pressure development before 40 h, although the absolute value obtained after 40 h is slightly overestimated. Additionally, the numerical results demonstrate a 47% removal efficiency of copper at the anode after 48 h, which is consistent with the experimental results. The distribution of electric field and contaminants are affected by the shape of the electrode board.

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引用次数: 0